Document pinctrl properties to support voltage-dependent pin
configuration switching for UHS-I SD card modes.
Add optional pinctrl-names property with two states:
- "default": For 3.3V operation with standard drive strength
- "state_uhs": For 1.8V operation with optimized drive strength
These pinctrl states allow the SDHCI driver to coordinate voltage
switching with pin configuration changes, ensuring proper signal
integrity during UHS-I mode transitions.
Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
.../devicetree/bindings/mmc/spacemit,sdhci.yaml | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
index 9a055d963a7f0cdba4741c1e3e7269688dcd5f45..932fccc609bf8dbaf3ecfe09d9e610852ac7afa0 100644
--- a/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
+++ b/Documentation/devicetree/bindings/mmc/spacemit,sdhci.yaml
@@ -11,6 +11,7 @@ maintainers:
allOf:
- $ref: mmc-controller.yaml#
+ - $ref: sdhci-common.yaml#
properties:
compatible:
@@ -44,6 +45,18 @@ properties:
- const: axi
- const: sdh
+ pinctrl-names:
+ minItems: 1
+ items:
+ - const: default
+ - const: uhs
+
+ pinctrl-0:
+ description: Default pinctrl state for 3.3V operation
+
+ pinctrl-1:
+ description: Optional pinctrl state for 1.8V UHS operation with "uhs" name
+
required:
- compatible
- reg
@@ -62,4 +75,7 @@ examples:
interrupt-parent = <&plic>;
clocks = <&clk_apmu 10>, <&clk_apmu 13>;
clock-names = "core", "io";
+ pinctrl-names = "default", "uhs";
+ pinctrl-0 = <&sdhci_default_cfg>;
+ pinctrl-1 = <&sdhci_uhs_cfg>;
};
--
2.53.0